Question 1

Which of the following statements best explains why Archaea are considered more closely related to Eukarya than to Bacteria?

Accepted Answer

Archaea and Eukarya share unique rRNA sequences not found in Bacteria.

Question 2

Which of the following equations represents oxygenic photosynthesis as carried out by cyanobacteria?

Accepted Answer

$$2H_2O + CO_2$ \xrightarrow{light} (CH_2O) + H_2O + O_2$

Question 3

A patient presents with a rapidly progressing wound infection after surgery. The bacteria isolated are Gram-positive cocci in clusters, resistant to multiple antibiotics, and produce an enterotoxin. Which organism is most likely responsible?

Accepted Answer

Staphylococcus aureus

Question 4

Which of the following best describes the role of heterocysts in filamentous cyanobacteria?

Accepted Answer

They are involved in nitrogen fixation under aerobic conditions.

Question 5

Which of the following bacteria is an obligate intracellular parasite that causes Rocky Mountain spotted fever?

Accepted Answer

Rickettsia rickettsii

Question 6

Which of the following is a distinguishing feature of the cell membrane lipids in Archaea compared to Bacteria?

Accepted Answer

Archaea have long-chain, branched hydrocarbons with ether linkages.

Question 7

Which of the following bacteria is responsible for the majority of foodborne illnesses due to its ability to ferment carbohydrates and its presence in the intestinal tract?

Accepted Answer

Escherichia coli

Question 8

A hospital outbreak of urinary tract infections is traced to a Gram-negative rod with swarming motility and concentric ring colony formation. Which organism is most likely involved?

Accepted Answer

Proteus vulgaris

Question 9

Which of the following best explains why Bacillus anthracis is able to persist in the environment for long periods?

Accepted Answer

It produces highly resistant endospores.

Question 10

Which of the following is true regarding the photosynthetic process in green and purple sulfur bacteria?

Accepted Answer

They use hydrogen sulfide as an electron donor and do not release oxygen.

Question 11

Which of the following diseases is caused by a spirochete and transmitted by ticks?

Accepted Answer

Lyme disease

Question 12

Which of the following is a medically significant consequence of Streptococcus mutans colonization in the human mouth?

Accepted Answer

Dental caries

Question 13

Which of the following best describes the main difference between oxygenic and anoxygenic photosynthesis?

Accepted Answer

Oxygenic photosynthesis uses $$H_2O as an $$electron donor and produces $$O_2$$; anoxygenic uses $$H_2S$$ and produces $$S^0.$$

Question 14

Which of the following bacteria is most likely to cause a severe eye infection in newborns if the mother is infected during childbirth?

Accepted Answer

Chlamydia trachomatis

Question 15

Which of the following is a unique feature of Mycoplasma pneumoniae compared to other bacteria?

Accepted Answer

It lacks a cell wall and is pleomorphic.

Question 16

Which of the following is the primary reason why Streptococcus pyogenes can cause necrotizing fasciitis (flesh-eating disease)?

Accepted Answer

It produces enzymes that destroy tissue.

Question 17

Which of the following is a medically important function of Streptomyces species?

Accepted Answer

They produce most of the antibiotics used in medicine.

Question 18

Which of the following best explains why Clostridium botulinum is a concern in improperly canned foods?

Accepted Answer

It is an obligate anaerobe that produces a potent neurotoxin.

Question 19

Which of the following is a common feature of all prokaryotes in the domains Bacteria and Archaea?

Accepted Answer

Lack of membrane-bound organelles

Question 20

Which of the following bacteria is most likely to be found in extremely salty environments such as salt ponds?

Accepted Answer

Extreme halophilic Archaea

Study Guide: The Prokaryotes – Domains Bacteria and Archaea

Study Guide - Practice Questions

Study Guide - Flashcards